Powered stapling device with rack release

ABSTRACT

A powered handle assembly includes a motor assembly, a rack, a shaft, and a pinion that couples the motor assembly to the rack. The shaft supports the pinion and is movable to move the pinion from a first position engaged with the rack to a second position disengaged from the rack to facilitate manual retraction of the rack.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.17/331,072, filed May 26, 2021, now U.S. Pat. No. 11,701,119, thedisclosure of which is incorporated by reference herein in its entirety.

FIELD

This disclosure is directed to powered surgical devices and, moreparticularly, to powered surgical stapling devices.

BACKGROUND

Various types of surgical devices used to endoscopically treat tissueare known in the art, and are commonly used, for example, for closure oftissue or organs in transection, resection, and anastomoses procedures,for occlusion of organs in thoracic and abdominal procedures, and forelectrosurgically fusing or sealing tissue.

One example of such a surgical device is a surgical stapling device.Typically, surgical stapling devices include a tool assembly having ananvil assembly and a cartridge assembly, and a drive assembly.Typically, the drive assembly includes a flexible drive beam and a clampmember that is supported on a distal end of the drive beam. The driveassembly is movable to advance the clamp member through the toolassembly to approximate the cartridge and anvil assemblies and toadvance an actuation sled through the cartridge assembly to ejectstaples from the cartridge assembly.

Surgical stapling devices can be manually actuated devices in which aclinician squeezes a trigger to actuate the stapling device, or poweredstapling devices in which a clinician activates a motor within thestapling device to actuate the stapling device. Although poweredstapling devices require less force to operate, difficulties may arisewhen the device loses power or components of the device break. In suchinstances, the device can remain clamped about tissue preventing removalof the device from a patient.

A continuing need exists in the art for a powered stapling device thatincludes a drive assembly that can be manually retracted when power islost or when the device is not operational.

SUMMARY

A surgical device includes a powered handle assembly having a motorassembly, a rack, a shaft, and a pinion that couples the motor assemblyto the rack. The shaft supports the pinion and is movable to move thepinion from a first position engaged with the rack to a second positiondisengaged from the rack to facilitate manual retraction of the rack.

One aspect of the disclosure is directed to a powered handle assemblyfor a surgical device including a housing, a gear casing, a motorassembly, a rack, a shaft, and a pinion. The housing defines a cavity.The gear casing is supported within the cavity of the housing anddefines a cavity and a longitudinal channel that extends through thecavity. The motor assembly includes an output shaft and a drive gearthat is secured to the output shaft. The motor assembly is secured tothe gear casing, and the drive gear is positioned within the cavity ofthe gear casing. The rack is received within the longitudinal channel ofthe gear casing and is movable through the cavity of the gear casingbetween retracted and advanced positions. The shaft extends through thecavity of the gear casing and is axially movable between first andsecond positions. The pinion is coupled to the shaft and is receivedwithin the cavity of the gear casing. The pinion is movable within thecavity of the gear casing, in response to movement of the shaft betweenits first and second positions, from a first position in which thepinion is engaged with the rack to a second position in which the pinionis disengaged from the rack.

Other aspects of the disclosure are directed to a surgical deviceincluding a powered handle assembly, an adapter assembly, and a toolassembly. The powered handle assembly includes a housing, a gear casing,a motor assembly, a rack, a shaft, and a pinion. The housing defines acavity. The gear casing is supported within the cavity of the housingand defines a cavity and a longitudinal channel that extends through thecavity of the gear casing. The motor assembly includes an output shaftand a drive gear that is secured to the output shaft. The motor assemblyis secured to the gear casing, and the drive gear is positioned withinthe cavity of the gear casing. The rack is received within thelongitudinal channel of the gear casing and is movable through thecavity of the gear casing between retracted and advanced positions. Theshaft extends through the cavity of the gear casing and is axiallymovable between first and second positions. The pinion is coupled to theshaft and is received within the cavity of the gear casing. The pinionis movable within the cavity of the gear casing, in response to movementof the shaft between its first and second positions, from a firstposition in which the pinion is engaged with the rack to a secondposition in which the pinion is disengaged from the rack. The adapterassembly includes a firing rod and has a proximal portion and a distalportion. The proximal portion of the adapter assembly is coupled to thehandle assembly. The firing rod is coupled to the rack and is movablebetween retracted and advanced positions in response to movement of therack between its retracted and advanced positions. The tool assembly issupported on the distal portion of the adapter assembly.

Other aspects of the disclosure are directed to a powered handleassembly for a surgical device including a housing, a motor assembly, arack, a shaft, and a pinion. The housing defines a cavity. The motorassembly includes an output shaft and a drive gear secured to the outputshaft. The rack is received within the cavity of the housing and ismovable between retracted and advanced positions. The shaft extendsthrough the cavity of the gear casing and is axially movable betweenfirst and second positions. The pinion is coupled to the shaft and ismovable, in response to movement of the shaft between its first andsecond positions, from a first position in which the pinion is engagedwith the rack to a second position in which the pinion is disengagedfrom the rack.

In aspects of the disclosure, the shaft is rotatably fixed to the gearcasing.

In some aspects of the disclosure, a biasing member is positioned withinthe cavity of the gear casing to urge the pinion towards its firstposition.

In certain aspects of the disclosure, the drive gear is engaged with thepinion such that rotation of the drive gear causes rotation of thepinion.

In aspects of the disclosure, the motor assembly includes a motor havinga motor shaft, a universal joint, a joint housing, and the output shaft,and the universal joint couples the motor shaft to the output shaft.

In some aspects of the disclosure, the motor shaft defines a first axis,and the output shaft defines a second axis, and the first axis definesan acute angle with the second axis.

In certain aspects of the disclosure, the output shaft of the motorassembly supports a first bevel gear, and the shaft supports a secondbevel gear that is engaged with the first bevel gear such that rotationof the first bevel gear causes rotation of the second bevel gear.

In aspects of the disclosure, the second bevel gear is fixedly securedto the shaft such that rotation of the second bevel gear causes rotationof the shaft and of the pinion.

In some aspects of the disclosure, the gear casing includes side walls,and each of the side walls supports a bearing.

In aspects of the disclosure, the shaft is rotatably supported betweenthe bearings on the gear casing.

Other features of the disclosure will be appreciated from the followingdescription.

BRIEF DESCRIPTION OF THE DRAWINGS

Various aspects of the disclosed stapling device are described hereinbelow with reference to the drawings, wherein:

FIG. 1 is a side perspective view of a first version of a staplingdevice according to aspects of the disclosure with the stapling devicein a non-articulated, unclamped position;

FIG. 2 is a side perspective view of the handle assembly of the staplingdevice shown in FIG. 1 with a housing half-section removed;

FIG. 3 is an exploded side perspective view of internal components ofthe handle assembly shown in FIG. 3 ;

FIG. 4 is a cross-sectional view taken along section line 4-4 of FIG. 2;

FIG. 5 is a cross-sectional view taken along section line 5-5 of FIG. 4;

FIG. 6 is a cross-sectional view taken along section line 6-6 of FIG. 5;

FIG. 7 is a side perspective view of the motor assembly of the staplingdevice shown in FIG. 1 with a joint casing shown in phantom;

FIG. 8 is a side perspective view of a reload assembly of the staplingdevice shown in FIG. 1 in the clamped and fired position;

FIG. 9 is a cross-sectional view taken along section line 9-9 of FIG. 8;

FIG. 10 is a cross-sectional view through a portion of the handleassembly shown in FIG. 1 with the stapling device in the clamped andfired position;

FIG. 11 is a side perspective view of a portion of the handle assemblyshown in FIG. 1 as the stapling device is manually retracted from theclamped and fired position;

FIG. 12 is an alternate version of the handle assembly of the staplingdevice shown in FIG. 1 including the motor assembly shown in FIG. 11with an alternate version of the rotating shaft;

FIG. 13 is a side perspective view of the rotating shaft of the handleassembly shown in FIG. 12 ;

FIG. 13A is perspective view of the handle assembly shown in FIG. 12with a housing of the handle assembly removed and a pinion in a firstposition;

FIG. 13B is a perspective view of the handle assembly shown in FIG. 12with the housing and gear casing removed and the pinion in a firstposition;

FIG. 13C is a cross-sectional view taken along section line 13C-13C ofFIG. 13A with the pinion in the first position;

FIG. 13D is a cross-sectional view taken along section line 13C-13C ofFIG. 13A with the pinion in a second position;

FIG. 14 is an alternate version of the handle assembly of the staplingdevice shown in FIG. 1 with a housing of the handle assembly shown inphantom;

FIG. 15 is an assembled, side perspective view of the internalcomponents of the handle assembly shown in FIG. 14 ;

FIG. 16 is an exploded side perspective view of internal components ofthe handle assembly shown in FIG. 15 ;

FIG. 17 is a cross-sectional view taken along section line 17-17 of FIG.15 ;

FIG. 18 is a side cross-sectional view of the drive assembly of thehandle assembly of the stapling device shown in FIG. 15 in the firedposition;

FIG. 18A is a side cross-sectional view through the drive assembly ofFIG. 14 illustrating the manual retract mechanism in the unlockedposition;

FIG. 19 another alternate version of the handle assembly of the staplingdevice shown in FIG. 1 with a housing of the handle assembly shown inphantom;

FIG. 20 is a side perspective view of a motor assembly and a driveassembly of the handle assembly shown in FIG. 19 with a gear casingremoved;

FIG. 21 is an exploded side perspective view of the drive assembly ofthe handle assembly shown in FIG. 19 ;

FIG. 22 is a side perspective view of the motor assembly and the driveassembly shown in FIG. 20 with the motor assembly actuated to advancethe drive assembly;

FIG. 23 is a plan view of the motor assembly and the drive assemblyshown in FIG. 23 with the motor assembly engaged with the driveassembly; and

FIG. 24 is a plan view of the motor assembly and the drive assemblyshown in FIG. 23 with the motor assembly disengaged with the driveassembly.

DETAILED DESCRIPTION

The disclosed surgical device will now be described in detail withreference to the drawings in which like reference numerals designateidentical or corresponding elements in each of the several views.However, it is to be understood that the aspects of the disclosure aremerely exemplary of the disclosure and may be embodied in various forms.Well-known functions or constructions are not described in detail toavoid obscuring the disclosure in unnecessary detail. Therefore,specific structural and functional details disclosed herein are not tobe interpreted as limiting, but merely as a basis for the claims and asa representative basis for teaching one skilled in the art to variouslyemploy the disclosure in virtually any appropriately detailed structure.In addition, directional terms such as front, rear, upper, lower, top,bottom, and similar terms are used to assist in understanding thedescription and are not intended to limit the disclosure.

In this description, the term “proximal” is used generally to refer tothat portion of the device that is closer to a clinician, while the term“distal” is used generally to refer to that portion of the device thatis farther from the clinician. In addition, the term “endoscopic” isused generally to refer to endoscopic, laparoscopic, arthroscopic,and/or any other procedure conducted through a small diameter incisionor cannula. Further, the term “clinician” is used generally to refer tomedical personnel including doctors, nurses, surgeons, and supportpersonnel.

This disclosure is directed to a surgical device that includes a poweredhandle assembly having a motor assembly, a rack, a spur gear, and amanual retract mechanism. The spur gear is movable from a positionengaged with the motor assembly and the rack to a positioned disengagedfrom the motor assembly and engaged with the rack to facilitate manualretraction of the rack. This disclosure is also directed to a surgicaldevice that includes a powered handle assembly having a motor assembly,a rack, a shaft, and a pinion that couples the motor assembly to therack. The shaft supports the pinion and is movable to move the pinionfrom a first position engaged with the rack to a second positiondisengaged from the rack to facilitate manual retraction of the rack.

FIG. 1 illustrates a surgical device shown generally as stapling device10 which includes a handle assembly 12, an elongate body or adapterassembly 14, and a tool assembly 16. The handle assembly 12 includes ahousing 18 that forms a stationary handle portion 18 a, an articulationlever 19, and actuation buttons 20. The adapter assembly 14 defines alongitudinal axis “X” and includes a proximal portion 24 that is coupledto the handle assembly 12, and a distal portion 26 that supports thetool assembly 16. The tool assembly 16 is secured to the distal portion26 of the adapter assembly 14 by a pivot member 28 that defines an axis“Y” that is transverse to the longitudinal axis “X”. The articulationlever 19 is operatively coupled to the tool assembly 16 via anarticulation linkage (not shown) such that manipulation of thearticulation lever 19 causes articulation of the tool assembly 16 aboutthe axis “Y” between a non-articulated position in which the toolassembly 16 is aligned with the longitudinal axis “Y” andnon-articulated positions in which a longitudinal axis of the toolassembly and the longitudinal axis “X” define acute angles. The adapterassembly 14 is supported within a rotation knob 30 that is rotatablycoupled to a distal portion of the handle assembly 12. The rotation knob30 is manually rotatable about the longitudinal axis “X” to rotate theadapter assembly 14 and the tool assembly 16 about the longitudinal axis“X”. The actuation buttons 20 control operation of the differentfunctions of the stapling device 10 including clamping and firing of thestapling device 10.

In aspects of the disclosure, the tool assembly 16 forms part of areload assembly 32 that includes a proximal body portion 34 and the toolassembly 16. The proximal body portion 34 of the reload assembly 32forms an extension of the adapter assembly 14 and includes a proximalend that is adapted to be releasably coupled to a distal end of theadapter assembly 14 and a distal end that supports the tool assembly 16for articulation. In aspects of the disclosure, the tool assembly 16 canbe fixedly coupled to a distal portion of the adapter assembly 14.

In aspects of the disclosure, the housing 18 of the handle assembly 12is formed from half-sections that are coupled together such as bywelding or using screws to define a cavity 38 (FIG. 2 ) that receivesinternal components of the handle assembly 12 which are described infurther detail below. The housing 18 defines an upper opening 40 thatprovides access to the internal components of the handle assembly 12.The upper opening 40 is enclosed by a cover 42 that is removablysupported within the upper opening 40.

FIGS. 2 and 3 illustrate the internal components of the handle assembly12 which include a gear casing 44, a motor assembly 46, a rack 48, afiring rod 50, a manual retract mechanism 52 and intermediate spur gear54, and a drive gear 56. The gear casing 44 is secured within the cavity38 of the housing 18 using screws or the like and defines a first cavity60 and a second cavity 62 that intersect with each other and alongitudinally extending channel 64. The first cavity 60 of the gearcasing 44 receives the drive gear 56 and the second cavity 62 of thegear casing 44 receives the intermediate spur gear 54. The drive gear 56and the intermediate spur gear each include gear teeth that mesh suchthat rotation of the drive gear 56 within the first cavity 60 causescorresponding rotation of the intermediate spur gear 54 within thesecond cavity 62. The rack 48 is received within the channel 64 of thegear casing 44 and includes gear teeth that mesh with the gear teeth ofthe intermediate spur gear 54. When the drive gear 56 is rotated torotate the intermediate spur gear 54, engagement between theintermediate spur gear 56 and the rack 48 causes the rack 48 to movelongitudinally through the channel 64 in the gear casing 44.

The motor assembly 46 includes an output shaft 70 (FIG. 4 ) that issecured to the drive gear 56 and can be activated via the actuationbuttons 20 (FIG. 1 ) to rotate the drive gear 56. In aspects of thedisclosure, the motor assembly 46 is positioned within a portion of thecavity 38 of the housing 18 defined by the stationary handle portion 18a. The motor assembly 46 includes a mounting bracket 72 that is securedto the gear casing 44 with screws 74 such that the drive gear 56 isreceived within the second cavity 62 of the gear casing 44.

FIGS. 3-6 illustrate the manual retract mechanism 52 which includes arotating shaft 78, a crank lever 80, and a grip member 82. The cranklever 80 includes a central hub portion 84 that defines a through bore86 that receives the rotating shaft 78. The through bore 86 includes acylindrical portion 86 a and a rectangular portion 86 b. The crank lever80 also includes a lever portion 88 that defines a slot 90 and forms aclevis 92. The grip member 82 is supported within the clevis 92 by apivot member 94 and is pivotable between a first position located withinthe slot 90 and a second position extending orthogonally from the leverportion 88.

The rotating shaft 78 includes a head portion 96 and a shaft portion 98that extends downwardly from the head portion 96 as viewed in FIG. 5through the through bore 86 in the crank lever 80. The shaft portion 98includes a first rectangular portion 100, a cylindrical portion 102, anda second rectangular portion 104. The second rectangular portion 104includes spaced annular grooves 106 and 108 that receive C-clips 110 and112, respectively. The intermediate spur gear 54 is received about thesecond rectangular portion 104 of the rotating shaft 78 atop the C-clip112 within the first cavity 60 of the gear casing 44. The C-clip 112 ispositioned externally of the first cavity 60 and secures the rotatingshaft 78 to the gear casing 44. Although the rotating shaft 78 is shownto have first and second rectangular portions, it is envisioned thatother shaft configurations are envisioned.

The gear casing 44 defines first and second openings 114 and 116 thatcommunicate with upper and lower ends of the first cavity 60 of the gearcasing 44. The cylindrical portion 102 of the rotating shaft 78 isreceived within the first opening 114 of the gear casing 44 and thesecond rectangular portion 104 of the rotating shaft 78 extends throughthe second opening 116 of the gear casing 44. The C-clip 110 (FIG. 5 )is secured to the lower end of the second rectangular portion 104 of therotating shaft 78 adjacent a lower surface of the gear casing 44 and theC-clip 112 is secured to the second rectangular portion 104 of therotating shaft 78 within the first cavity 60 of the gear casing 44. TheC-clips 110 and 112 secure the intermediate spur gear 54 to the rotatingshaft 78 and secure the rotating shaft 78 to the gear casing 44. Thesecond rectangular portion 104 of the rotating shaft 78 is receivedwithin a rectangular bore in the intermediate spur gear 54 to rotatablyfix the intermediate spur gear 54 to the rotating shaft 78.

The intermediate spur gear 54 is received within the first cavity 60 ofthe gear casing 44 and is movable within the first cavity between afirst or lower position and a second or upper position. In the lowerposition (FIG. 5 ), the teeth of the intermediate spur gear 54simultaneously engage the teeth of the rack 48 and the teeth of thedrive gear 56. In the upper position, the teeth of the intermediate spurgear 54 engage only the teeth of the rack 48.

The manual retract mechanism 52 includes a biasing member 120 that ispositioned between an upper surface of the intermediate spur gear 54 andthe inner surface of the gear casing 44. The biasing member 120 urgesthe intermediate spur gear 54 towards its lower position in which theintermediate spur gear 54 is engaged with both the drive gear 56 and therack 48. In some aspects of the disclosure, a washer 122 is positionedbetween an upper surface of the biasing member 120 and the inner surfaceof the gear casing 44. In certain aspects of the disclosure, the biasingmember 120 includes a coil spring. It is envisioned that other types ofbiasing members could be incorporated into the stapling device 10 (FIG.1 ).

The rack 44 includes a distal portion that is coupled to the firing rod50. In aspects of the disclosure, the proximal portion of the firing rod50 is formed with a head 124 (FIG. 3 ) that has a diameter that islarger than a body of the firing rod 50, and the distal portion of therack 48 defines a slot 128. The head 124 of the firing rod 50 isreceived within the slot 128 of the rack 48 to couple the firing rod 50to the rack 48 such that longitudinal movement of the rack 48 causeslongitudinal movement of the firing rod 50. The coupling of the head 124and the slot 128 allows the firing rod 50 to rotate in relation to therack 48.

In some aspects of the disclosure, the manual retract mechanism 52includes a base member 130 that defines a circular bore 132 (FIG. 3 ).The base member 130 is secured to an upper surface of the gear casing 44and the hub portion 84 of the crank lever 80 is aligned within thecircular bore 132. The crank lever 80 is movable from a lowered positionto a raised position. In the lowered position, the hub portion 84 of thecrank lever 80 is received within the circular bore 132 and in theraised position, the hub portion 84 of the crank lever 80 is positionedabove the circular bore 132 of the base member 130.

The head 96 of the rotating shaft 78 of the manual retract mechanism 52is received within the bore 86 of the crank lever 80. When the cranklever 80 is in its lowered position, the cylindrical portion 102 of therotating shaft 78 is received within the rectangular portion 86 b (FIG.5 ) of the through bore 86 of the crank lever 80. In this position, therotating shaft 78 can rotate within the through bore 86 of the cranklever 80 without causing rotation of the crank lever 80. When the cranklever 80 is moved to its raised position, the first rectangular portion100 (FIG. 3 ) of the rotating shaft 78 is received within therectangular portion 86 b of the through bore 86 of the crank lever 80.In this position, rotation of the crank lever 80 causes correspondingrotation of the rotating shaft 78, and thus, rotation of theintermediate spur gear 54. The head 96 of the rotating shaft 78 has adiameter that is larger than the width of the rectangular portion 86 bof the through bore 86 of the crank lever 80. Thus, movement of thecrank lever 80 to its raised position causes the rotating shaft 78 tomove to its upper position in which the teeth of the intermediate spurgear 54 are only engaged with the teeth of the rack 48.

FIG. 7 illustrates the motor assembly 46 which includes a motor 142, amotor shaft 144, a universal joint 146, a joint housing 148 and themotor assembly output shaft 70. As described above, the motor assemblyoutput shaft 70 supports the spur gear 54. The universal joint 146,e.g., a Cardan joint, couples the motor shaft 144 to the motor assemblyoutput shaft 70 to translate rotation of the motor shaft 144 intorotation of the motor assembly output shaft 70. The universal joint 144allows a longitudinal axis of the motor shaft 144 to be positioned at anangle to a longitudinal axis of the motor assembly output shaft 70. Themotor 142 of the motor assembly 46 is supported within the stationaryhandle portion 18 a of the handle assembly 12. The universal joint 146allows the stationary handle portion 18 a (FIG. 2 ) to be angled inrelation to the longitudinal axis of the stapling device 10 (FIG. 1 ) toprovide a more ergonomic grip configuration on the handle assembly 12 ofthe stapling device 10.

The handle assembly 12 (FIG. 1 ) also includes one or more batteries 140(FIG. 2 ) which are received within the cavity 38 of the housing 18 ofthe handle assembly 12. The batteries 140 provide power to the motorassembly 46 via the actuation switches 20 (FIG. 1 ) and controlcircuitry (not shown), e.g., a printed circuit board and one or morecontrollers, positioned within the handle assembly 12 to control firingof the stapling device 10.

FIGS. 4-6 illustrate the handle assembly 12 of the stapling device 10(FIG. 1 ) with the stapling device 10 in an unclamped position prior tofiring of the stapling device. In this position, the rack 48 is in aretracted position within the channel 64 of the gear casing 44 and theintermediate spur gear 54 is in its lowered position and is engaged withthe rack 48 and the drive gear 56.

FIGS. 8 and 9 illustrate the reload assembly 32 when the stapling device10 is in a fired position. As described above, the reload assembly 32includes the tool assembly 16 and the proximal body portion 34. Inaspects of the disclosure, the tool assembly 16 includes an anvilassembly 150 and a cartridge assembly 152. The cartridge assembly 152includes a staple cartridge 154 that supports a plurality of staples andpushers (not shown), and an actuation sled 156. The proximal bodyportion 34 includes a drive assembly 158 that includes a flexible beam160 and a working end 162. The working end 162 of the drive assembly 158has an I-beam configuration and is secured to a distal end portion ofthe flexible beam 160. The flexible beam 160 has a proximal end portionthat is releasably coupled to a distal portion of the firing rod 50.When the firing rod 50 is moved from a retracted position to an advancedposition, the drive assembly 158 moves from a retracted position to anadvanced position to move the working end 162 of the drive assembly 158through the tool assembly 16 to advance the actuation sled 156 throughthe tool assembly 16. As the actuation sled 156 moves through the toolassembly 16, the actuation sled 156 engages the pushers (not shown) toeject staples (not shown) from the staple cartridge 154 into the anvilassembly 150. In the fired position, the working end 162 of the driveassembly 158 and the actuation sled 156 are in their advanced positionswithin the tool assembly and the tool assembly 16 is in the clampedposition clamped about tissue (not shown). For a more detaileddescription of the operation of the drive assembly 158 and itsinteraction with the tool assembly, see U.S. Pat. No. 8,132,706.

FIG. 10 illustrates the handle assembly 12 of the stapling device 10(FIG. 1 ) as the stapling device 10 is fired. When the stapling device10 is fired, the intermediate spur gear 54 (FIG. 4 ) is engaged with therack 48 and with the drive gear 56. When the motor assembly 46 isactivated, the drive gear 56 rotates the intermediate spur gear 54 toadvance the rack 48 in the direction indicated by arrows “A”. The rack48 is coupled to the firing rod 50 such that advancement of the firingrod 50 causes advancement of the rack 48 to advance the firing rod 50 inthe direction of arrows “A” and advance the drive assembly 158 (FIG. 11) within the tool assembly 16.

FIG. 11 illustrates the manual retract mechanism 52 as it is readied foruse. When the stapling device 10 loses power or gets damaged such thatthe motor assembly 46 cannot retract the drive assembly 158 to releasetissue clamped between the anvil and cartridge assemblies 150 and 152(FIG. 11 ), the manual retract mechanism 52 can be operated to retractthe drive assembly 158 (FIG. 11 ). In order to access the manual retractmechanism 52, the cover 42 (FIG. 1 ) is removed to uncover the upperopening 40 in the housing 18 of the handle assembly 12. Once the coveris removed, the crank lever 80 is pulled upwardly in the direction ofarrow “C” to move the crank lever 80 from its lowered position to itsraised position. As the crank lever 80 is moved towards its raisedposition, the first rectangular portion 100 (FIG. 3 ) of the rotatingshaft 78 is received in the rectangular portion 86 b (FIG. 3 ) of thethrough bore 86 in the crank lever 80. Once the first rectangularportion 100 of the rotating shaft 78 is received in the rectangularportion 86 b of the through bore 86 in the crank lever 80, continuedmovement of the crank lever 80 in the direction of arrow “C” will liftthe rotating shaft 78 and the intermediate spur gear 54 to their upperpositions compressing the biasing member 120 (FIG. 5 ). In the upperposition, the intermediate spur gear 54 is disengaged from the drivegear 56 and is engaged only with the rack 48. Once the crank lever 80 isin its raised position, the grip member 82 can be pivoted in thedirection of arrow “D” about the pivot member 94 to an operationalposition.

Once the crank lever 80 is moved to its raised position, the crank lever80 can be rotated to rotate the rotating shaft 78 and the intermediatespur gear 54 to retract the rack 48. More specifically, when the cranklever 80 is rotated, receipt of the first rectangular portion 100 (FIG.3 ) of the rotating shaft 78 in the rectangular portion 86 b of thethrough bore 86 of the crank lever 80 rotatably fixes the crank lever 80to the rotating shaft 78. Thus, when the crank lever 80 rotates, therotating shaft 78 also rotates. The intermediate spur gear 54 isrotatably fixed to the rotating shaft 78 via receipt of the secondrectangular portion 104 of the rotating shaft 78 in the rectangular bore54 a (FIG. 3 ) of the intermediate spur gear 54 such that rotation ofthe rotating shaft 78 causes rotation of the intermediate spur gear 54.In its upper position, the intermediate spur gear 54 is only engagedwith the rack 48, and as such, rotation of the intermediate spur gear 54causes retraction of the rack 48.

FIGS. 12-13D illustrate an alternate version of the handle assembly 12(FIG. 2 ) of the stapling device 10 (FIG. 1 ) shown generally as handleassembly 212. The handle assembly 212 includes a housing 214 that issubstantially like housing 18 (FIG. 1 ) of stapling device 10. Thehousing 214 defines a cavity 216 that receives the internal componentsof the handle assembly 212 and an opening 260 that is enclosed by acover 262.

The handle assembly 212 includes a motor assembly 220 that is receivedwithin the cavity 216 and includes an output shaft (not shown) thatrotates a drive gear 222 (FIG. 13B). The motor assembly 220 and thedrive gear 222 are substantially like the motor assembly 46 and drivegear 56 described above and will not be described in further detailherein.

The handle assembly 212 includes a gear casing 224 that defines a cavity226 and a longitudinal channel 228. The drive assembly 218 of the handleassembly 212 includes a spur gear or pinion 230 and a rack 232. Thepinion 230 is engaged with the drive gear 222 such that rotation of thedrive gear 222 causes rotation of the pinion 230. The pinion 230 is alsorotatably supported within the cavity 226 of the gear casing 224 about ashaft 234 and is movable within the cavity 226 between a first position(FIG. 13C) and a second position (13D). The rack 232 extends through thelongitudinal channel 228 in the gear casing 224 and includes teeth 232 athat are engaged with the pinion 230 when the pinion 230 is in its firstposition and disengaged from the pinion 230 when the pinion 230 is inits second position.

The shaft 234 (FIG. 13 ) extends through a non-circular bore 236 definedin the gear casing 224 and includes a head 238, a non-circular shaftportion 240, and a cylindrical portion 242. The non-circular shaftportion 240 of the shaft 234 defines a shoulder 240 a (FIG. 13D) that ispositioned adjacent to the circular portion 242 of the shaft 234. Thenon-circular shaft portion 240 of the shaft 234 is slidably received inthe non-circular bore 236 of the gear casing 224 such that the shaft 234is rotatably fixed to the gear casing 224 but slidable within thenon-circular bore 236 between raised and lowered positions. In aspectsof the disclosure, the non-circular bore 236 of the gear casing 224 andthe non-circular shaft portion 240 of the shaft 234 have correspondingD-shaped configurations although other configurations are envisioned.The cylindrical portion 242 of the shaft 234 defines an annular groove244 (FIG. 13C).

The pinion 230 defines a central bore 248 (FIG. 13C) that receives andis rotatable about the cylindrical portion 242 of the shaft 234. Abiasing member, e.g., a coil spring 250 (FIG. 12 ) is positioned withinthe cavity 226 of the gear casing 224 between a casing wall 226 a (FIG.12) and a side of the pinion 230 opposite to the head 238 of the shaft234. The coil spring 250 is in compression and urges the pinion 230 toits first position in which the pinion 230 is engaged with the rack 232.A washer 252 is received within the annular groove 244 formed in thecylindrical portion 242 of the shaft 234. The cylindrical portion 242 ofthe shaft 234 extends through a bore 256 (FIG. 13C) in a bottom of thegear casing 224, and the washer 252 is positioned externally of thecavity 226 of the gear casing 224 to secure the shaft 234 to the gearcasing 224.

When the motor assembly 220 is activated, the drive gear 222 (FIG. 13B)which is engaged with the pinion 230 (FIG. 13C) is rotated to rotate thepinion 230. When the pinion 230 is in its first position engaged withthe rack 232 (FIG. 13C), rotation of the pinion 230 causes longitudinalmovement of the rack 232. It is noted that the shoulder 240 a of thenon-circular portion 240 of the shaft 234 is engaged with the top of thepinion 230 when the pinion 230 is in its first position.

When the stapling device 10 (FIG. 1 ) loses power or gets damaged suchthat the motor assembly 220 cannot retract the drive assembly 218 torelease tissue clamped between the anvil and cartridge assemblies 150and 152 (FIG. 11 ), the cover 260 (FIG. 12 ) in the housing 214 of thehandle assembly 212 can be removed to uncover the opening 262 (FIG. 12 )in the housing 214 to provide access to the head 238 of the shaft 234.To manually retract the rack 232, the shaft 234 can be presseddownwardly in the direction of arrow “G” in FIG. 13D to move the pinion230 downwardly within the cavity 226 of the gear casing 224 from itsfirst position to its second position. More particularly, when the shaft234 is pressed downwardly, the shoulder 240 a on the shaft 234 pressesdownwardly on the pinion 230 to compress the coil spring 250 and movethe pinion 230 to its second position disengaged from the rack 232.

Once the pinion 230 is disengaged from the rack 232, the rack 232 can bepulled or driven proximally using any known retraction means, e.g., aratchet/pawl mechanism, a hooked tool, or the like, to move the driveassembly 158 of the tool assembly 16 (FIG. 8 ) from the clamped positionto the unclamped position. It is noted that additional openings may becreated in the housing 214 of the handle assembly 212 to access theretraction means.

FIGS. 14-18 illustrate a stapling device 300 including an alternateversion of the handle assembly shown generally as handle assembly 312.The handle assembly 312 includes a housing 314 that is substantiallylike housing 18 (FIG. 1 ) of stapling device 10 and will not bedescribed in further detail herein. The housing 314 defines a cavity 316that receives the internal components of the handle assembly 312.

FIGS. 14-16 illustrate the internal components of the handle assembly312 which includes a motor assembly 318, a drive assembly 320, and amanual retract mechanism 322. The motor assembly 318 is supported withinthe cavity 316 (FIG. 18 ) of the housing 314 and includes an outputshaft 324 that has a flat surface 324 a. In some aspects of thedisclosure, the output shaft 324 (FIG. 16 ) has a D-shaped configurationalthough other configurations are envisioned.

The drive assembly 320 is coupled to the output shaft 324 of the motorassembly 318 and includes a one-way spur gear 328, a drive screw 330, adrive nut 332, connecting rods 334, a coupling member 336, a guide tube338, and a gear casing 340. The gear casing 340 includes a mountingflange 342 and a cylindrical body 344. The mounting flange 342 of thegear casing 340 defines bores 346 that receive screws 348. The screws348 are received in threaded bores 350 formed in a distal face of themotor assembly 318 to secure the gear casing 340 to the motor assembly318. The cylindrical body 344 of the gear casing 340 defines a cavity352 and a window 354 that communicates with the cavity 352. Thecylindrical body 344 of the gear casing 340 defines two openings 356(only one is shown) and two cutouts 358. One of the openings 356 and oneof the cutouts 358 is positioned on each side of the window 354 invertical alignment with each other. The cavity 352 of the cylindricalbody 344 of the gear casing 340 receives the one-way spur gear 328. Thedistal portion of the cylindrical body 344 of the gear casing 340supports a bearing 359.

The one-way spur gear 328 defines a central through bore 360 thatreceives a bearing 362. In aspects of the disclosure, the centralthrough bore 360 and the bearing 362 have corresponding non-circularconfigurations, e.g., D-shaped configurations, such that the bearing 362is slidably received within the central through bore 360 of the one-wayspur gear 328. The corresponding configurations of the one-way spur gear328 and the bearing 362 rotatably fix the components to each other. Thebearing 362 also defines a central through bore 364 that has anon-circular configuration.

The drive screw 330 includes a threaded outer surface 366, a proximalextension 368, and a distal extension 370. The proximal extension 368 ofthe drive screw 330 extends through the bearing 359 within the gearcasing 340 and is received and secured within the central through bore364 of the bearing 364. The distal extension 370 of the drive screw 330is received within a bearing 372 that is supported within the housing314 (FIG. 16 ) to rotatably support the drive screw 330 within thehousing 314.

When the motor assembly 318 is activated to rotate the output shaft 324,rotation of the output shaft 324, when engaged with the one-way spurgear 328, causes corresponding rotation of the one-way spur gear 328. Asdescribed above, the one-way spur gear 328 is rotatably fixed to thebearing 362 which is secured to and rotatably fixed to the drive screw330. As such, rotation of the one-way spur gear 328 causes correspondingrotation of the drive screw 330.

The drive nut 332 includes a threaded bore 374 that receives and isthreadably engaged with the threaded outer surface 366 of the drivescrew 330. The drive nut 332 is coupled to a proximal portion of theconnecting rods 334. In aspects of the disclosure, the drive nut 332includes protrusions 378 that are received within openings 380 formed inthe proximal portions of the connecting rods 334 to connect the drivenut 332 to the connecting rods 334. The connecting rods 334 extenddistally from the drive nut 332 and include distal portions that areconnected to the coupling member 336. In aspects of the disclosure, thecoupling member 336 includes protrusions 384 that are received withinopenings 386 formed in the distal portions of the connecting rods 334 toconnect the coupling member 336 to the connecting rods 334. The drivenut 332 and the connecting rods 334 are received within the guide tube338.

When the drive screw 330 is rotated, engagement between the outerthreaded surface 366 of the drive screw 330 and the inner threaded bore374 of the drive nut 332 causes the drive nut 332 to translatelongitudinally along the drive screw 330 within the guide tube 338. Thedrive nut 332 is connected to the connecting rods 334 such thatlongitudinal translation of the drive nut 332 along the drive screw 330causes the connecting rods 334 to move longitudinally within the guidetube 338 to advance to coupling member 336.

The coupling member 336 is coupled to a firing rod 382 (FIG. 17 ) suchthat longitudinal movement of the coupling member 336 causeslongitudinal movement of the firing rod 382. In aspects of thedisclosure, the firing rod 382 includes a head portion 384 and anelongate body 386. The head portion 384 has a diameter that is greaterthan a diameter of the elongate body 386. The coupling member 336defines a slot 390 that has a width that is greater than the diameter ofthe elongate body 386 but less than the diameter of the head portion384. The elongate body 386 of the firing rod 382 is received through theslot 390 in the coupling member 336 to axially fix the firing rod 382 tothe coupling member 336 while allowing relative rotation of the firingrod 382 and the coupling member 336.

The one-way spur gear 328 is movably positioned within the cavity 352 ofthe cylindrical body 344 of the gear casing 340 between a retractedposition (FIG. 17 ) and an advanced position (FIG. 18A). In theretracted position, the one-way spur gear 328 is engaged with theproximal extension 368 of the drive screw 330 and the output shaft 324of the motor assembly 318 such that rotation of the output shaft 324 ofthe motor assembly 324 causes rotation of the drive screw 330. In theadvanced position, the one-way spur gear 328 is disengaged from theoutput shaft 324 of the motor assembly 318 but still engaged with thedrive screw 330. A biasing member 396, e.g., a coil spring, ispositioned between the distal surface of the motor assembly 318 and aproximal surface of the one-way spur gear 328 to urge the one-way spurgear 328 towards the advanced position. In aspects of the disclosure,the proximal surface of the one-way spur gear 328 defines a recess 328 a(FIG. 18A) that receives the biasing member 396.

FIGS. 16-18A illustrate the manual retract mechanism 322 which includesa pawl assembly 410 and a locking clip 412. The pawl assembly 410includes a handle 414 and a body portion 416. In aspects of thedisclosure, the body portion 416 has an oval or annular configurationand supports a ratcheting pawl 418 that is pivotably secured to an upperportion of the body portion 416 by a pivot member 420 (FIG. 16 ). Theratcheting pawl 418 extends downwardly into a circular opening definedby the body portion 416. The body portion 416 is received about the gearcasing 340 with the ratcheting pawl 418 positioned over the window 354in the gear casing 340 above the one-way spur gear 328. A lower portionof the body portion 416 defines a circular slot 422.

The locking clip 412 has a rectangular shape and includes a base portion426 and spaced legs 428 that extend upwardly from the base portion 426.Each of the legs 428 of the locking clip 412 includes a stepped innersurface 430 that includes a first surface 430 a and a second surface 430b. The first surfaces 430 a of the legs 428 are spaced to define a firstwidth and the second surfaces 430 b are spaced to define a second widththat is greater than the first width. Each of the legs 428 is receivedthrough one of the openings 356 and cutouts 358 of the gear casing 340such that the stepped inner surfaces 430 of the legs 428 of the lockingclip 412 are positioned within the cavity 352 of the gear casing 340.The locking clip 412 is movable from a first position in which the firstsurfaces 430 a of the legs 428 of the locking clip 412 are aligned withthe one-way spur gear 328 and a second position in which the secondsurfaces 430 b of the legs 428 of the locking clip 412 are spaced fromthe one-way spur gear 328. The width defined between the first surfaces430 a of the legs 428 of the locking clip 412 is such to preventmovement of the one-way spur gear 328 to its advanced position, whereasthe width defined between the second surfaces 430 b of the legs 428 ofthe locking clip 412 allows movement of the one-way spur gear 328 to theadvanced position.

The base portion 426 of the locking clip 412 includes a protrusion 434(FIG. 16 ) that is received within the circular slot 422 (FIG. 18A) inthe body portion 416 of the pawl assembly 410. Receipt of the protrusion434 couples the pawl assembly 410 to the locking clip 412 to retain thepawl assembly 410 in a stable position about the gear casing 340. Theprotrusion 434 is configured to slide within the circular slot 422 asdescribed in further detail below.

FIG. 17 illustrates the drive assembly 320 in a pre-fired position withthe pawl assembly 410 positioned about the gear casing 340 and theratcheting pawl 418 positioned above the window 354 (FIG. 16 ) in thegear casing 340. When the handle assembly 312 (FIG. 14 ) is assembled,the one-way spur gear 328 is pressed proximally towards the motorassembly 318 to compress the biasing member 396 and position the one-wayspur gear 328 in its retracted position. After the one-way spur gear 328is in its retracted position, the legs 428 (FIG. 16 ) of the lockingclip 412 are inserted from a side of the gear casing 340 opposite to theratcheting pawl 418 into the openings 356 and cutouts 358 formed in thegear casing 340 to its first position. In the first position of thelocking clip 412, the first surfaces 430 a of the legs 428 of thelocking clip 412 engage a distal face of the one-way spur gear 328 toretain the one-way spur gear 328 in its retracted position against theurging of the biasing member 396. In its retracted position, the one-wayspur gear 328 is engaged with both the output shaft 324 of the motorassembly 318 and the one-way spur gear 328. When the locking clip 412 isin its first position, the protrusion 434 on the locking clip 412 ispressed into the circular slot 422 on the body portion 416 of the pawlassembly 410 to couple the pawl assembly 410 to the locking clip 412(FIG. 18A).

In the pre-fired position of the handle assembly 12 (FIG. 17 ), thedrive nut 332 is positioned near the proximal end of the drive screw 330and the coupling member 336 is positioned adjacent the distal end of theguide tube 338 such that the connecting rods 334 are in retractedpositions and the firing rod 382 is in its retracted position.

FIG. 18A illustrates the handle assembly 312 (FIG. 14 ) in a firedposition. When the stapling device 300 (FIG. 14 ) is fired by pressingthe actuation buttons 302, the motor assembly 318 (FIG. 16 ) isactivated to rotate the output shaft 324. Rotation of the output shaft324 causes corresponding rotation of the one-way spur gear 328 and thedrive screw 330 to advance the drive nut 332 along the drive screw 330in the direction of arrow “J”. As the drive screw 330 advances the drivenut 332, the drive nut 332 advances the connecting rods 334 to advancethe firing rod 382 in the direction of arrow “K” and actuate the toolassembly 306 (FIG. 14 ) as described above regarding tool assembly 16 ofthe stapling device 10 (FIG. 1 ).

When the tool assembly 316 is in the clamped and fired position (FIG. 8) and the powered stapling device 300 (FIG. 14 ) becomes inoperable andcannot be unclamped using the motor assembly 318, the manual retractmechanism 322 allows the tool assembly to be manually unclamped. Tooperate the manual retract mechanism 322, the pawl assembly 410 ispressed downwardly in the direction of arrow “L” in FIG. 18A. When thepawl assembly 410 is pressed downwardly, the locking clip 412, which iscoupled to the pawl assembly 410 by the protrusion 434, is moved fromits first position to its second position. In its second position, thelocking clip 412 disengages from the one-way spur gear 328 such that thebiasing member 396 moves the one-way spur gear 328 from its retractedposition to its advanced position. In its advanced position, the one-wayspur gear 328 is disengaged from the output shaft 324 of the motorassembly 318. When the pawl assembly 410 is pressed downwardly, theratcheting pawl 418 moves through the window 354 of the gear housing 340into engagement with the one-way spur gear 328.

After the one-way spur gear 328 is in its advanced position, the handle414 of the pawl assembly 410 can be rotated to rotate the one-way spurgear 328 and the drive screw 330 to retract the firing rod 382. As thepawl assembly 410 is rotated, the protrusion 434 (FIG. 18A) moves withinthe circular slot 422 of the pawl assembly 410.

FIGS. 19-24 illustrate a stapling device 500 including an alternateversion of the handle assembly of the stapling device 10 shown generallyas handle assembly 512. The handle assembly 512 includes a housing 514that is substantially like housing 18 (FIG. 1 ) of stapling device 10and will not be described in further detail herein. The housing 514defines a cavity 516 that receives the internal components of the handleassembly 512. The cavity 516 is accessible through an opening (notshown) in the housing 514 which is enclosed by a cover (not shown).

The handle assembly 512 includes a motor assembly 520 that is receivedwithin the cavity 516 of the handle assembly 512 and includes an outputshaft 522 (FIG. 21 ) that rotates a drive gear shown as bevel gear 524.The motor assembly 520 is like the motor assembly 46 described abovewill not be described in further detail herein.

The handle assembly 512 includes a gear casing 526 that defines a cavity528 and a longitudinal channel 530. The drive assembly 518 of the handleassembly 512 includes a bevel gear 532 and a rack 534. The bevel gear532 of the drive assembly 518 is engaged with the bevel gear 524 of themotor assembly 520 such that rotation of the bevel gear 524 causesrotation of the bevel gear 532. The bevel gear 532 is also rotatablysupported within the cavity 528 of the gear casing 526 about a shaft 536and is movable within the cavity 528 between a first position (FIG. 23 )and a second position (FIG. 24 ). The shaft 536 includes a head 536 athat is positioned adjacent the opening 580 in the housing 514. The rack534 extends through the longitudinal channel 530 in the gear casing 526and includes teeth 534 a. The rack 534 includes a distal portion 538that is coupled to a proximal portion 540 a of a firing rod 540.

The shaft 536 is rotatably supported between two side walls 542 a and542 b of the gear casing 526 and supports a pinion or spur gear 544.Each of the side walls 542 a and 542 b of the gear casing 526 defines acircular opening 546 (only one is shown) that receives a bearing 548 a,548 b (FIG. 21 ). The bearings 548 a, 548 b are secured within theopenings 546 of the gear casing 526 by retaining plates 550 a and 550 bthat are secured to the side walls 542 a and 542 b of the gear casing526 by screws 552. The bearings 548 define bores 554 that receive theends of the shaft 536.

The shaft 536 includes a D-shaped portion 556 and defines an annulargroove 558 (FIG. 21 ). The D-shaped portion 556 has an end that isreceived within a D-shaped bore 560 formed in the bevel gear 532 of thedrive assembly 518 to secure the shaft 536 to the bevel gear 532 suchthat rotation of the bevel gear 532 causes rotation of the shaft 536.The D-shaped portion 556 of the shaft 536 is also received within aD-shaped bore 562 formed in the pinion 544 such that rotation of theshaft 536 causes corresponding rotation of the pinion 544. The annulargroove 558 in the shaft 536 receives a C-clip 566 to secure the pinion544 on the shaft 536.

The pinion 544 is secured on the shaft 536 within the cavity 528 of thegear casing 526. The shaft 536 is movable within the bores 554 of thebearings 548 between first and second positions to move the pinion 544between first and second positions. In the first position of the shaft536 and the pinion 544 (FIG. 23 ), the pinion 544 is engaged with theteeth 534 a of the rack 534 such that rotation of the pinion 544 causeslongitudinal movement of the rack 534 within the longitudinal channel530 of the gear casing 526. In the second position of the shaft 536 andthe pinion 544, the pinion 544 is disengaged from the rack 534. Abiasing member, e.g., a coil spring 570, is supported within the cavity528 of the gear casing 526 between the side wall 542 a of the gearcasing 526 and the pinion 544 to urge the pinion 544 towards the firstposition.

FIGS. 22 and 23 illustrate the drive assembly 518 of the handle assembly512 (FIG. 19 ) with the shaft 536 and the pinion 544 urged to the firstposition by the coil spring 570 (FIG. 21 ). As described above, when theshaft 536 and the pinion 544 are in their first positions, the pinion544 is engaged with the rack 534. When the motor assembly 520 isactuated to rotate the motor assembly bevel gear 524 in the direction ofarrow “K” in FIG. 22 , the drive assembly bevel gear 532 is rotated torotate the shaft 536 in the direction of arrow “L” in FIG. 22 . When theshaft 536 is rotated, the pinion 544 which is secured to the shaft 536is rotated to move the rack 534 longitudinally in the direction of arrow“M”. The rack 534 is coupled to the firing rod 540. As such,longitudinal movement of the rack 534 causes corresponding longitudinalmovement of the firing rod 540 to actuate the tool assembly 16 (FIG. 8 )as described above.

When the stapling device 500 (FIG. 19 ) loses power or gets damaged suchthat the motor assembly 520 cannot retract the drive assembly 518 torelease tissue clamped between the anvil and cartridge assemblies 150and 152 (FIG. 11 ), the cover (not shown) in the housing 514 of thehandle assembly 512 can be removed to uncover the opening (not shown) inthe housing 514 to provide access to the head 536 a of the shaft 536. Tomanually retract the rack 534, the shaft 536 can be pulled outwardly inthe direction of arrow “J” in FIG. 24 to move the pinion 544 within thecavity 528 of the gear casing 526 from its first position to its secondposition in the direction of arrows “K” and disengage the pinion 544from the rack 534.

Once the pinion 544 is disengaged from the rack 534, the rack 534 can bepulled or driven proximally using any known retraction means, e.g., aratchet/pawl mechanism, a hooked tool, or the like, to move the driveassembly 518 of the tool assembly 16 (FIG. 8 ) from the clamped positionto the unclamped position. It is noted that additional openings may becreated in the housing 514 of the handle assembly 512 to access theretraction means and/or the rack 534.

Persons skilled in the art will understand that the devices and methodsspecifically described herein and illustrated in the accompanyingdrawings are non-limiting exemplary aspects of the disclosure. It isenvisioned that the elements and features illustrated or described inconnection with one exemplary aspect of the disclosure may be combinedwith the elements and features of another without departing from thescope of the disclosure. As well, one skilled in the art will appreciatefurther features and advantages of the disclosure based on theabove-described aspects of the disclosure. Accordingly, the disclosureis not to be limited by what has been particularly shown and described,except as indicated by the appended claims.

1. (canceled)
 2. A surgical device comprising: a handle assemblyincluding: a housing; a motor assembly having an output shaft; a drivescrew defining a longitudinal axis; a drive nut movable along the drivescrew in response to rotation of the drive screw between a nut retractedposition and a nut advanced position; a coupling member secured to thedrive nut such that movement of the drive nut between the nut retractedposition and the nut advanced position causes movement of the couplingmember between a coupling retracted position and a coupling advancedposition; a spur gear secured to the drive screw such that rotation ofthe spur gear about the longitudinal axis causes rotation of the drivescrew about the longitudinal axis, the spur gear movable between a firstposition engaged with the output shaft of the motor assembly and asecond position disengaged from the output shaft of the motor assembly;and a pawl assembly including a ratcheting pawl, the pawl assemblymovable from a first pawl position disengaged from the spur gear to asecond pawl position engaged with the spur gear, the pawl assemblyoperable to rotate the spur gear about the longitudinal axis when thepawl assembly is in the second pawl position; an elongate body extendingfrom the handle assembly, the elongate body including a firing rod thatis secured to the coupling member, the firing rod movable between a rodretracted position and a rod advanced position in response to movementof the coupling member between the coupling retracted position and thecoupling advanced position; and a tool assembly supported on theelongate body, the firing rod movable from the rod retracted position tothe rod advanced position to actuate the tool assembly.
 3. The surgicaldevice of claim 2, further including a biasing member positioned to urgethe spur gear towards the second position.
 4. The surgical device ofclaim 3, further including a locking clip positioned to retain the spurgear in the first position.
 5. The surgical device of claim 4, whereinthe locking clip includes a base member and a pair of legs that extendfrom the base member, the legs including first portions and secondportions, the first portions defining a first distance therebetween andthe second portions defining a second distance therebetween, the seconddistance greater than the first distance, wherein the first portions arepositioned to engage the spur gear to retain the spur gear in the firstposition.
 6. The surgical device of claim 5, wherein the locking clip ismovable from a first clip position in which the first portions areengaged with the spur gear to a second clip position in which thelocking clip is disengaged from the spur gear.
 7. The surgical device ofclaim 6, wherein movement of the pawl assembly from the second pawlposition to the first pawl position moves the locking clip from thefirst clip position to the second clip position.
 8. The surgical deviceof claim 2, wherein the handle assembly further includes a gear casing,and the spur gear is movable within the gear casing.
 9. The surgicaldevice of claim 8, wherein the gear casing defines a window, and theratcheting pawl of the pawl assembly extends through the window.
 10. Thesurgical device of claim 8, wherein the gear casing is secured to themotor assembly and the output shaft of the motor assembly is receivedwithin the gear casing.
 11. The surgical device of claim 2, wherein thetool assembly includes an anvil and a cartridge assembly.
 12. Thesurgical device of claim 2, wherein the handle assembly includesconnecting rods, the connecting rods securing the coupling member to thedrive nut.
 13. A handle assembly for a surgical device comprising: ahousing; a motor assembly having an output shaft; a drive screw defininga longitudinal axis; a drive nut movable along the drive screw inresponse to rotation of the drive screw between a nut retracted positionand a nut advanced position; a coupling member secured to the drive nutsuch that movement of the drive nut between the nut retracted positionand the nut advanced position causes movement of the coupling memberbetween a coupling retracted position and a coupling advanced position;a spur gear secured to the drive screw such that rotation of the spurgear about the longitudinal axis causes rotation of the drive screwabout the longitudinal axis, the spur gear movable between a firstposition engaged with the output shaft of the motor assembly and asecond position disengaged from the output shaft of the motor assembly;and a pawl assembly including a ratcheting pawl, the pawl assemblymovable from a first pawl position disengaged from the spur gear to asecond pawl position engaged with the spur gear, the pawl assemblyoperable to rotate the spur gear about the longitudinal axis when thepawl assembly is in the second pawl position.
 14. The handle assembly ofclaim 13, further including a biasing member positioned to urge the spurgear towards the second position.
 15. The handle assembly of claim 13,further including a locking clip positioned to retain the spur gear inthe first position, the locking clip having a base member and a pair oflegs that extend from the base member, the legs including first portionsand second portions, the first portions defining a first distancetherebetween and the second portions defining a second distancetherebetween, the second distance greater than the first distance,wherein the first portions are positioned to engage the spur gear toretain the spur gear in the first position.
 16. The handle assembly ofclaim 15, wherein the locking clip is movable from a first clip positionin which the first portions are engaged with the spur gear to a secondclip position in which the locking clip is disengaged from the spurgear, and movement of the pawl assembly from the second pawl position tothe first pawl position moves the locking clip from the first clipposition to the second clip position.
 17. The handle assembly of claim13, wherein the handle assembly further includes a gear casing, and thespur gear is movable within the gear casing.
 18. The handle assembly ofclaim 17, wherein the gear casing defines a window, and the ratchetingpawl of the pawl assembly extends through the window.
 19. The handleassembly of claim 18, wherein the gear casing is secured to the motorassembly and the output shaft of the motor assembly is received withinthe gear casing.
 20. The handle assembly of claim 13, further includingconnecting rods, the connecting rods securing the coupling member to thedrive nut.
 21. A handle assembly for a surgical device comprising: ahousing; a motor assembly having an output shaft; a drive screw defininga longitudinal axis; a drive nut movable along the drive screw inresponse to rotation of the drive screw between a nut retracted positionand a nut advanced position; a spur gear secured to the drive screw suchthat rotation of the spur gear about the longitudinal axis causesrotation of the drive screw about the longitudinal axis, the spur gearmovable between a first position engaged with the output shaft of themotor assembly and a second position disengaged from the output shaft ofthe motor assembly; and a pawl assembly including a ratcheting pawl, thepawl assembly movable from a first pawl position disengaged from thespur gear to a second pawl position engaged with the spur gear, the pawlassembly operable to rotate the spur gear about the longitudinal axiswhen the pawl assembly is in the second pawl position.